A significant number of compounds are known to be useful in providing a cooling sensation in the mouth, in the nasal cavity and/or on skin. The best known and most widely used of these is menthol which in addition to olfaction caused a cooling response on cold receptors in the oral cavity, the nasal cavity and on skin.
In the field of flavors and fragrances for consumer products such as foodstuffs, beverages, tobacco products and personal care products there has always been great interest in compounds having a physiological cooling activity on the nervous system of the body, especially of the skin and the mucosa of the oral cavity, similar to that obtained with menthol.
Such compounds may be added to ingestible preparations, to tobacco products, and/or to products applied to the skin, for the purpose of stimulating the cold receptors of the nervous system in the surface tissues of the mucosa of the oral cavity or the skin, thereby creating a sensation of coolness and/or freshness in the mouth or on the skin.
Menthol has been used extensively for this purpose, and mainly as a fortifier for peppermint flavours (see “Perfume and Flavour Chemicals, Volume II, by Steffen Arctander, published 1969, Item No. 1840) but also in trace amounts in imitation butter, caramel, fruit complexes and licorice flavourings. Menthol is well known for its physiological cooling effect on the skin and mucous membranes of the mouth and has been extensively used as a flavouring agent (menthol being a major constituent of oil of peppermint) in foodstuffs, beverages, dentifrices, mouthwashes, etc. and as a component in a wide range of toiletries, liniments and lotions for topical application. Menthol is also a well known tobacco additive for producing a “cool” sensation in the mouth when smoking.
It is well established that the “cooling” effect of menthol is a physiological effect due to the direct action of menthol on the nerve endings of the human body responsible for the detection of hot or cold and is not due to latent heat of evaporation. It is believed that the menthol acts as a direct stimulus on the cold receptors at the nerve endings which in turn stimulate the central nervous system.
Although menthol is well established as a physiological coolant, its use in some compositions is impaired by its strong minty odour and its relative volatility.
A variety of compounds are known which provide a cooling sensation when ingested or contacted with the body. Perhaps the best known of these compounds is menthol. It is believed that menthol acts on the cold receptors at the nerve endings in order to provide this cooling effect.
Since menthol has a strong minty odor and high relative volatility, several other coolant compounds have been developed and reported in the technical literature as potential flavorants or odorants in a variety of topical and ingestible compositions. For example, U.S. Pat. No. 5,009,893 proposes the use of menthol in combination with N-substituted-p-menthane carboxamide compounds as coolant compositions in edible products.
Thus, varieties of compounds are known which provide cooling properties and are useful in a wide variety of products. However, there is still a need to provide coolant compositions having an improved cooling effect and/or taste perception.